xxii 



studies, but still as one who by his great natural abilities, and 

 especially by the force of his strong character, bade fair to make his 

 mark somewhere. 



In the October term of that year he went into residence at Trinity 

 College, Cambridge, his college tutor being Mr. J. Prior. He early 

 placed himself under the private tuition of Mr. Marlborough Pryor 

 (who had just been elected the first Natural Science Fellow at Trinity 

 College), and after passing, at Christmas, the " Previous Examina- 

 tion," devoted himself entirely to natural science. In Mr. Marl- 

 borough Pryor he found a friend of remarkably wide knowledge and 

 sound judgment, who not only so well directed his pupil's studies, 

 that at Easter, Balfour was, without hesitation, elected Natural 

 Science Scholar at his college, but carefully matured those higher 

 scientific qualities which are rarely tested in any examination. 



After Christmas Balfour attended the lectures of Dr. Michael 

 Foster, who had been called to Trinity College, Cambridge, as Praa- 

 lector, at the same time that Balfour entered as a student. In a 

 course of lectures on embryology, given by the latter in the following 

 Easter term, Balfour was especially interested, and he soon after 

 definitely made up his mind to devote himself to the study of animal 

 morphology. 



Before long he was invited by Dr. Foster to join him in pre- 

 paring for publication the lectures on embryology, which the latter 

 had given, and with that end in view began original inquiry by 

 attempting to investigate certain obscure points in the history of the 

 chick. The res alts of these studies were subsequently published in 

 the " Quarterly Journal of Microscopical Science " (July, 1873), as 

 three papers " On the Development and Growth of the Layers of 

 the Blastoderm," "On the Disappearance of the Primitive Grroove in 

 the Embryo Chick," and " On the Development of the Blood-vessels 

 of the Chick." Some of the views enunciated in these early papers 

 were naturally modified by later experience, but the observations on 

 the primitive streak are interesting as forming the starting point of 

 views which Balfour developed more fully afterwards. 



These investigations, and others not recorded in any special papers, 

 but made use of in the little work "Elements of Embryology" 

 (1874), by Dr. Foster and himself, occupied so much of Balfour's 

 time and energy, that he was unable to do much in the way of 

 formal preparation for his degree. Nevertheless, he nearly suc- 

 ceeded in obtaining the first place in the Natural Sciences Tripos 

 in December, 1873; this fell to Mr. H. Newell-Martin, now 

 Professor at Baltimore, United States, America, Balfour being placed 

 second. Immediately after his degree he started, in company with 

 his friend Mr. A. Dew-Smith, for Naples, to occupy at the Statione 

 Zoologica of Dr. Anton Dohrn one of the tables at the disposal of 



